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emm
Hooked
Joined: 11 Oct 2006
Posts: 34
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 Posted: Sat Dec 30, 2006 12:07 am Post subject: X-Treme Dec 29 |
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I’ve just looked at the solution to see where I went wrong on Dec 29 XT.
This is what I did - Type 3 UR -78- -> r5c4 cannot be 5 leaving 8.
| Code: |
*--------------------------------------------------------------------*
| 678 389 469 | 2 1 5 | 4679 389 4678 |
| 128 238 159 | 6 4 7 | 19 158 38 |
| 1567 47 146 | 3 8 9 | 167 125 4567 |
|----------------------+----------------------+----------------------|
| 4 1 78* | 578* 35 2 | 358 6 9 |
| 3 6 2 | 58 9 4 | 58 7 1 |
| 9 5 78* | 178* 36 16 | 38 4 2 |
|----------------------+----------------------+----------------------|
| 27 89 3 | 15# 56 16 | 247 289 478 |
| 1567 47 1456 | 9 2 8 | 167 135 3567 |
| 1568 289 1569 | 4 7 3 | 1269 189 568 |
*--------------------------------------------------------------------*
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However the solution has r5c4 = 5 so … you can’t use URs on diagonals?? |
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Ruud
Site Owner
Joined: 30 Dec 2005
Posts: 601
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| Posted: Sat Dec 30, 2006 11:14 am Post subject: |
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The intended deadly pattern has a single cell in each diagonal, which means that one of the diagonals has a 7 outside the pattern and the other has an 8. These force the pattern to a single solution.
In Sudoku-X, it is not possible to form URs with cells that belong to one of the diagonals, but they could be used in larger deadly patterns (BUG Lite), like this example:
| Code: | X . .|. X .|. . .
. . .|. . .|. . .
. . X|. X .|. . .
-----+-----+-----
. . .|. . .|. . .
X . X|. . .|. . .
. . .|. . .|. . .
-----+-----+-----
. . .|. . .|. . .
. . .|. . .|. . .
. . .|. . .|. . . |
But these are very rare, I think. |
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emm
Hooked
Joined: 11 Oct 2006
Posts: 34
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| Posted: Sun Dec 31, 2006 7:21 pm Post subject: |
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Thanks Ruud.
Can you tell me how to get the rating on these puzzles. If I put them into SudoCue and click analyzer they all say easy  I know that's not right!! My screen doesn't seem to show a rating in the bottom RH corner as it supposedly should.
Funny that our New Year is already in and you guys are just winding up!
Happy New Year already! |
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emm
Hooked
Joined: 11 Oct 2006
Posts: 34
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| Posted: Tue Jan 02, 2007 4:50 am Post subject: |
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... in the meantime ... I'll rate them myself
X-Treme Advanced
A = 'Aven't got a clue!
B = By golly that took ages!
C = Could it be I'm improving?
D = Doddle
1.1.07 = D
 |
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emm
Hooked
Joined: 11 Oct 2006
Posts: 34
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| Posted: Tue Jan 02, 2007 6:41 pm Post subject: |
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2.1.07 = C
dum de dum dum de dum |
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sudokuEd
Grandmaster
Joined: 19 Jun 2006
Posts: 257
Location: Sydney Australia
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| Posted: Tue Jan 02, 2007 9:17 pm Post subject: |
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Still stuck on the December 29 X-treme. emm, FYI, SudoCue rates it as "Unfair 6951" - or "EA" on your rating scale. Thankfully not eA! eA would have to be Oct 23 X-treme I'd think 
Anyway, this is where I've been able to get to for Dec 29 X-treme. Help appreciated.
| Code: | .---------------.---------------.---------------.
| 68 389 469 | 2 1 5 | 4679 389 4678|
| 128 23 159 | 6 4 7 | 19 158 38 |
| 1567 47 146 | 3 8 9 | 16 2 456 |
:---------------+---------------+---------------:
| 4 1 78 | 578 35 2 | 358 6 9 |
| 3 6 2 | 58 9 4 | 58 7 1 |
| 9 5 78 | 178 36 16 | 38 4 2 |
:---------------+---------------+---------------:
| 27 89 3 | 15 56 16 | 247 89 47 |
| 167 47 1456| 9 2 8 | 167 135 356 |
| 1568 289 1569| 4 7 3 | 1269 189 568 |
'---------------'---------------'---------------' |
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Ruud
Site Owner
Joined: 30 Dec 2005
Posts: 601
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| Posted: Tue Jan 02, 2007 10:08 pm Post subject: |
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| sudokuEd wrote: | Still stuck on the December 29 X-treme.
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I have been experimenting with a new Almost Locked Candidates move. You gave me a marvelous example:
| Code: | .---------------.---------------.---------------.
| 68 389 469 | 2 1 5 |-4679 389 4678|
| 128 23 159 | 6 4 7 |$19 158 38 |
| 1567 47 146 | 3 8 9 |$16 2 456 |
:---------------+---------------+---------------:
| 4 1 78 | 578 35 2 | 358 6 9 |
| 3 6 2 | 58 9 4 | 58 7 1 |
| 9 5 78 | 178 36 16 | 38 4 2 |
:---------------+---------------+---------------:
| 27 89 3 | 15 56 16 | 247 *89 47 |
| 167 47 1456| 9 2 8 | 167 *135 *356 |
| 1568 289 1569| 4 7 3 | 1269*189 *568 |
'---------------'---------------'---------------' |
I love the logic behind this move 
There is an ALS in box 9, 5 starred cells with candidates digits 135689. Of these digits, 358 appear nowhere else in the box, and 169 only appear in the intersection with column 7, so this intersection must contain one of these digits 169.
Further in column 7, there is an ALS marked with $ for digits 169. This set requires 2 of the digits 169.
As a result, digits 169 cannot appear anywhere else in column 7, allowing us to eliminate candidates 6 & 9 from r1c7.
Any questions? 
_________________
“If the human brain were so simple that we could understand it, we would be so simple that we couldn't.” - Emerson M Pugh |
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sudokuEd
Grandmaster
Joined: 19 Jun 2006
Posts: 257
Location: Sydney Australia
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| Posted: Wed Jan 03, 2007 7:01 am Post subject: |
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| emm on Oct 23 thread wrote: | | Ruud said that his XY ALS was more appropriate than the 2XY example in your thread. Maybe yours is the adult version. Very Happy |
If mine was the adult version, Ruud has finally shown us the X-rated adult version. That is a really nice hidden triple, ALSxyz.
Now you've inspired me to find my own moves
1. 2 9's in n3
1a. 9 in r1c8 -> r2c1279 = {1238} -> no 8 in r2c8
1b. 9 in r2c7 -> r1c8 & r2c9 = {38} -> no 8 in r2c8.
1c. -> no 8 in r2c8.
1d. -> naked triple {159} r2 -> no 1 in r2c1
2. 2 8's in r2 -> a strong links X-wing thingo move eliminates 8 from r5c4
2a. 8 in r2c1 -> 8 in D\ must be in r4c4 or r9c9 and in D/ in r1c9 or r6c4. They can't both be in c9 -> an 8 must be in r4c4 or r6c4 -> no 8 in r5c4
2b. 8 in r2c9, exactly the mirror situation occurs for c1 -> 8 must be in r4c4 or r6c4 -> no 8 in r5c4
2c. -> no 8 in r5c4
2d. -> r5c7 = 8
then, its slow and steady progress to the end.
Thanks for a ripper Ruud. Been really enjoying these X-tremes. Seems to be one of these RA rated XT's a week
Last edited by sudokuEd on Wed Jan 03, 2007 10:35 pm; edited 2 times in total |
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emm
Hooked
Joined: 11 Oct 2006
Posts: 34
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| Posted: Wed Jan 03, 2007 6:01 pm Post subject: |
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V nice move Ruud - I'm finding the ALS really hard to find - apart from little XYwing ones. Are there any clues for spotting them?
PS: 3.1.07 XT = B (finally did it with UR). Any thoughts on how I can rate these?
PPS: I like my new shade of indigo!! |
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Para
Yokozuna
Joined: 08 Nov 2006
Posts: 384
Location: The Netherlands
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| Posted: Wed Jan 03, 2007 6:37 pm Post subject: |
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| sudokuEd wrote: |
If mine was the adult version, Ruud has finally shown us the X-rated adult version. That is a really nice hidden triple, ALSxyz.
Now you've inspired me to find my own moves
1. 2 9's in n3
1a. 9 in r1c8 -> r2c1279 = {1238} -> no 8 in r2c8
1b. 9 in r2c7 -> r1c8 & r2c9 = {38} -> no 8 in r2c8.
1c. -> no 8 in r2c8.
1d. -> naked triple {159} r2 -> no 1 in r2c1
2. 2 8's in r2 -> a strong links X-wing thingo move eliminates 8 from r5c4
2a. 8 in r2c1 -> 8 in D\ must be in r4c4 or r9c9 and in D/ in r1c9 or r6c4. They can't both be in c9 -> an 8 must be in r4c4 or r6c4-> no 8 in r5c4
2b. 8 in r2c9, exactly the mirror situation occurs for c1 -> 8 must be in r4c4 or r6c4-> no 8 in r5c4
2c. -> no 8 in r5c4
2d. -> r5c7 = 8
then, its slow and steady progress to the end.
Thanks for a ripper Ruud. Been really enjoying these X-tremes. Seems to be one of these RA rated XT's a week |
Step one can be recreated by the XYZ-wing using R17C8 and R2C9.
| Code: | .---------------.---------------.---------------.
| 68 389 469 | 2 1 5 | 4679 389* 4678|
| 128 23 159 | 6 4 7 | 19 15-8 38* |
| 1567 47 146 | 3 8 9 | 16 2 456 |
:---------------+---------------+---------------:
| 4 1 78 | 578 35 2 | 358 6 9 |
| 3 6 2 | 58 9 4 | 58 7 1 |
| 9 5 78 | 178 36 16 | 38 4 2 |
:---------------+---------------+---------------:
| 27 89 3 | 15 56 16 | 247 89* 47 |
| 167 47 1456| 9 2 8 | 167 135 356 |
| 1568 289 1569| 4 7 3 | 1269 189 568 |
'---------------'---------------'---------------' |
Para
ps
Nice elimination with the 8 in R5C4. After that it goes swiftly. Ruud's elimination of the 6 and 9 is a bit too big for me but it isn't needed. Eliminated them another way after a few more steps. |
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Para
Yokozuna
Joined: 08 Nov 2006
Posts: 384
Location: The Netherlands
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| Posted: Wed Jan 03, 2007 8:43 pm Post subject: |
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| sudokuEd wrote: |
If mine was the adult version, Ruud has finally shown us the X-rated adult version. That is a really nice hidden triple, ALSxyz.
Now you've inspired me to find my own moves
1. 2 9's in n3
1a. 9 in r1c8 -> r2c1279 = {1238} -> no 8 in r2c8
1b. 9 in r2c7 -> r1c8 & r2c9 = {38} -> no 8 in r2c8.
1c. -> no 8 in r2c8.
1d. -> naked triple {159} r2 -> no 1 in r2c1
2. 2 8's in r2 -> a strong links X-wing thingo move eliminates 8 from r5c4
2a. 8 in r2c1 -> 8 in D\ must be in r4c4 or r9c9 and in D/ in r1c9 or r6c4. They can't both be in c9 -> an 8 must be in r4c4 or r6c4-> no 8 in r5c4
2b. 8 in r2c9, exactly the mirror situation occurs for c1 -> 8 must be in r4c4 or r6c4-> no 8 in r5c4
2c. -> no 8 in r5c4
2d. -> r5c7 = 8
then, its slow and steady progress to the end.
Thanks for a ripper Ruud. Been really enjoying these X-tremes. Seems to be one of these RA rated XT's a week |
I tried to solve it without this elimination and came up with another way to get past this point.
This is another way to get past step 2.
Coloring for digit 7 eliminates the 7 in R6C4. This give a 7 in R4C4 and R6C3 and an 8 in R4C3.
| Code: |
.---------------.---------------.---------------.
| 68 389 469 | 2 1 5 | 4679 389 467A8|
| 128 23 159 | 6 4 7 | 19 15 38 |
| 1567 47 146 | 3 8 9 | 16 2 456 |
:---------------+---------------+---------------:
| 4 1 78 | 57B8 35 2 | 358 6 9 |
| 3 6 2 | 58 9 4 | 58 7 1 |
| 9 5 78 | 1-78 36 16 | 38 4 2 |
:---------------+---------------+---------------:
| 27 89 3 | 15 56 16 | 247 89 47B |
| 167 47 1456| 9 2 8 | 167 135 356 |
| 1568 289 1569| 4 7 3 | 1269 189 568 |
'---------------'---------------'---------------'
|
Then you get this. R1C1 and R9C9 are the only 8's on D\ and so there can't be any 8's in R1C9 and R9C1 which leaves a single 8 in R6C4 on the D/. Then you are able to fill boxes 5, 6 and 8.
| Code: |
.---------------.---------------.---------------.
| 68* 389 469 | 2 1 5 | 4679 389 467-8|
| 128 23 159 | 6 4 7 | 19 15 38 |
| 1567 47 146 | 3 8 9 | 16 2 456 |
:---------------+---------------+---------------:
| 4 1 8 | 7 35 2 | 35 6 9 |
| 3 6 2 | 58 9 4 | 58 7 1 |
| 9 5 7 | 18! 36 16 | 38 4 2 |
:---------------+---------------+---------------:
| 27 89 3 | 15 56 16 | 24 89 47 |
| 167 47 1456| 9 2 8 | 167 135 356 |
| 156-8 289 1569| 4 7 3 | 1269 189 568*|
'---------------'---------------'---------------'
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I think i am going to try some more X-files puzzles. This one kinda inspired me. 
Para |
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Ruud
Site Owner
Joined: 30 Dec 2005
Posts: 601
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| Posted: Wed Jan 03, 2007 9:56 pm Post subject: |
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indigo girl, rating these puzzles is difficult because not all solving techniques recognize the diagonals. SudoCue often uses a more advanced technique like Multi-Colors when an easier pattern using the diagonals is present. When I solve these puzzles manually, I often find such shortcuts. Also, all the puzzles were rated using an earlier version of SudoCue which did not yet support the latest semi-advanced techniques.
In general: The diagonal constraints completely change the frequency in which the solving techniques occur. For instance, I found several Sue de Coq moves, sometimes with alternative ALC moves in Sudoku-X, which are very rare in regular Sudoku.
Anyhow, my X-Tremes collection is like a box of chocolates: you never know what you will get.
Ruud
_________________
“If the human brain were so simple that we could understand it, we would be so simple that we couldn't.” - Emerson M Pugh |
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sudokuEd
Grandmaster
Joined: 19 Jun 2006
Posts: 257
Location: Sydney Australia
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| Posted: Thu Jan 04, 2007 12:17 am Post subject: |
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| Para wrote: | | Step one can be recreated by the XYZ-wing using R17C8 and R2C9. |
Thanks for pointing that one out Para. I havn't come across XYZ-wing - but it's not nearly as complicated as the name suggests. A simple pattern -> findable.
| Para wrote: | | Ruud's elimination of the 6 and 9 is a bit too big for me |
Too adult for me too at the moment - but its great fun to know about many different ways to solve the same puzzle. Very encouraging.
| Para wrote: | This is another way to get past step 2.
Coloring for digit 7 eliminates the 7 in R6C4. |
Really like this move too - missed that. But again, very findable. |
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emm
Hooked
Joined: 11 Oct 2006
Posts: 34
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| Posted: Thu Jan 04, 2007 5:09 am Post subject: |
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Ruud - that's what I thought - but someone else I know rates them and I just wondered if I could too. No worries, not knowing is half the fun!
Here's my move to eliminate the 69 in N3. I wasn't going to show off but since Para did I'm going to - don't I just have to be like everyone else!!
Strong links on 7s N3 and N5 -> r7c7 <> 7
-> r4c4 = 7
-> hidden pr 47 on D/
-> naked pr 47 in c9
-> hidden pr 47 in N3
-> r1c7 <> 69
PS: 4.1.07 XT is a Caramello |
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Para
Yokozuna
Joined: 08 Nov 2006
Posts: 384
Location: The Netherlands
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| Posted: Fri Jan 05, 2007 2:09 am Post subject: |
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| Ruud wrote: | The intended deadly pattern has a single cell in each diagonal, which means that one of the diagonals has a 7 outside the pattern and the other has an 8. These force the pattern to a single solution.
In Sudoku-X, it is not possible to form URs with cells that belong to one of the diagonals, but they could be used in larger deadly patterns (BUG Lite), like this example:
| Code: | X . .|. X .|. . .
. . .|. . .|. . .
. . X|. X .|. . .
-----+-----+-----
. . .|. . .|. . .
X . X|. . .|. . .
. . .|. . .|. . .
-----+-----+-----
. . .|. . .|. . .
. . .|. . .|. . .
. . .|. . .|. . . |
But these are very rare, I think. |
I found one in december 16th X-treme
| Code: |
. . .|. . 8|2 6 .
. . 5|9 . 2|4 . .
. 7 .|4 . .|. . .
-----+-----+-----
. 6 2|. 1 .|. . .
. . .|8 . .|. . .
4 5 .|. . .|. . .
-----+-----+-----
1 2 .|. . .|. . 6
7 . .|. . .|. . .
. . .|. . .|3 . . |
Solved it till here and then one is there.
| Code: |
.------------------.------------------.------------------.
| 39 349 349 | 1 5 8 | 2 6 7 |
| 6 1 5 | 9 7 2 | 4 8 3 |
| 2 7 8 | 4 3 6 | 1 59 59 |
:------------------+------------------+------------------:
| 8 6 2 | 35 1 34 | 579 34579 459 |
| 39 39 1379 | 8 6 3457 | 57 123-45* 12-45*|
| 4 5 137 | 2 9 37 | 6 13 8 |
:------------------+------------------+------------------:
| 1 2 349 | 35 8 359 | 579 579 6 |
| 7 349 34 | 6 24* 1359 | 8 24* 159 |
| 5 8 6 | 7 24* 19 | 3 19 24* |
'------------------'------------------'------------------'
|
2 naked pairs 2-4 on R89C5 and R8C8/R9C9 and 2 locked in R5C89 eliminates the 4 from R5C89 because it would form a (non-)unique pattern otherwise.
This was just as example.
Para |
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